Scribe street seals in semiconductor devices and method of fabrication

Abstract

An integrated circuit wafer, covered by a protective overcoat, comprising an array of integrated circuit chips bordered by seal regions and separated by dicing lines; at least two sets of substantially parallel structures within each of said seal regions, each set extending along the edge of a chip on opposite sides of each said dicing line, respectively; each of said sets comprising at least one continuous barrier wall adjacent each chip, respectively; at least one sacrificial composite structure in combination therewith, between said wall and the center of said dicing line, said composite structure being a discontinuous barrier wall comprising metal rivets interconnecting electrically conductive layers in an alternating manner, whereby said composite structure provides mechanical strength to said sets and simultaneously disperses the energy associated with crack propagation; and at least one slot opened into said protective overcoat, reaching from the surface of said overcoat at least to the surface-nearest electrically conductive layer of said composite structure, whereby cracks propagating in said protective overcoat will be stopped.

Description

FIELD OF THE INVENTIONThe present invention is related in general to the field of semiconductor devices and processes and more specifically to the fabrication of integrated circuit chips protected against potential damage caused by the propagation of cracks initiated by the step of separating semiconductor wafers into individual chips.DESCRIPTION OF THE RELATED ARTWith most semiconductor products, for example integrated circuits, transistors and diodes, a large number of elements are manufactured simultaneously on a large semiconductor wafer of silicon, silicon germanium, gallium arsenide, etc. The semiconductor industry employs the terms “dicing technologies” or “scribing technologies” to refer to those techniques for obtaining a large number of functional chips, or dies, from each semiconductor wafer. Two dicing methods are particularly well known in the art: The grinding-cutting method, using a blade or wire saw, and the scribing method, using a diamond point. Modern silicon tech...

AI Technical Summary

Benefits of technology

The present invention comprises sacrificial structures for arresting insulator cracks in semiconductor circuit chips and methods for fabricating reinforced insulators in semiconductor wafers. It has particular application to dicing multilevel metal semiconductor wafers into individual circuit chips. The invention permits the introduction of electrically advantageous, but mechanically brittle insulators into the production of large-area, high-speed integrated circuits without risking reliability degradation through propagating cracks initiated by the dicing process.

In an additional embodiment of the invention, the sacrificial structure is in electrical contact with a highly doped region of the semiconductor wafer. Electrical potential, such as ground potential, can thus be applied to the sacrificial structure, effectively stopping the drift of unwanted charged particles.

Problems solved by technology

Since dicing streets are well-known areas for the generation of microcracks, they are prime concerns for latent failures of the semiconductor device due to propagating cracks.

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